Many women (estimated at approximately 52% of post-pubescent females) suffer painful menstruation or dysmenorrhea. Of these women, over 50% experience other systemic symptoms, often including indicators of affected gastrointestinal (GI) functioning such as nausea, vomiting, diarrhea, and constipation. The proposed study will focus on comparison of GI functioning during the menstrual cycle in menstruating women who complain of moderate to severe dysmenorrhea to normal menstruating women with no dysmenorrhea, and to menstruating women taking ovarian hormones and women past the stage of hormone cycling. The specific aims of the study are: 1. to describe and compare GI function during two menstrual cycles in women complaining of dysmenorrhea to women with no complaints of dysmenorrhea. GI function will be assessed by measurement of intragastric pressure changes at two points in the menstrual cycle. Subjects will also keep daily stool records; 2. to determine whether GI function is related to naturally fluctuating levels of ovarian hormones; 3. to describe the prevalence of general menstrual symptoms in the perimenstrum and in the intermenstrum; 4. to determine if GI contractile activity and bowel patterns are associated with the prevalence of general menstrual symptoms. The study is expected to provide information on the normal cyclic changes in the GI tract which may occur in response to ovarian hormones. Such information would be of value to health care providers in assessing normal bowel function in a significant population of women. There is an apparent need to distinguish between normal changes in GI function and that which occurs in dysmenorrheic women who experience vomiting and diarrhea during menses. The study could provide the basis from which to study potential problems with nutrient and drug absorption during the menstrual cycle, as well as research directed at determining the mechanism of action.